Over the last 50 years, obesity has been increasing at an alarming rate and is now recognized by leading government health authorities, such as the Centers for Disease Control (CDC) and National Institutes of Health (NIH), as a disease. In the United States alone, obesity affects more than 60 million individuals and is considered the second leading cause of preventable death. Worldwide, approximately 1.6 billion adults are overweight, and it is estimated that obesity affects at least 400 million adults.
Obesity is caused by a wide range of factors including genetics, metabolic disorders, physical and psychological issues, lifestyle, and poor nutrition. Millions of obese and overweight individuals first turn to diet, fitness and medication to lose weight; however, these efforts alone are often not enough to keep weight at a level that is optimal for good health. Surgery is another increasingly viable alternative for those with a Body Mass Index (BMI) of greater than 40. In fact, the number of bariatric surgeries in the United States is projected to reach approximately 400,000 annually in 2010.
Examples of surgical methods and devices used to treat obesity include the LAP-BAND® (Allergan, Inc., Irvine, Calif.) gastric band and the LAP-BAND AP® (Allergan, Inc., Irvine, Calif.). However, surgery might not be an option for every obese individual; for certain patients, non-surgical therapies or minimal-surgery options are more effective or appropriate.
Intragastric balloons are also well known in the art as a means for treating obesity. One such inflatable intragastric balloon is described in U.S. Pat. No. 5,084,061 and is commercially available as the BioEnterics Intragastric Balloon System (sold under the trademark BIB® System). These devices are designed to provide therapy for moderately obese individuals who need to shed pounds in preparation for surgery, or as part of a dietary or behavioral modification program. The BIB System, for example, consists of a silicone elastomer intragastric balloon that is inserted into the stomach in an empty or deflated state and thereafter filled (fully or partially) with a suitable fluid. The balloon occupies space in the stomach, thereby leaving less room for food and creating a feeling of satiety for the patient.
Another type of surgical device for treating obesity is a duodenal sleeve, which is a flexible tube endoscopically placed in and along the duodenum, which is located at the beginning of the intestinal tract, to slow down or interrupt the digestive process which occurs there. Examples of such devices include those shown in U.S. Pat. No. 5,820,584 to Crabb and U.S. Pat. No. 7,476,256 to Meade, et al. Duodenal sleeves require some sort of anchor to prevent migration down the intestinal tract, typically utilizing a metallic stent with barbs as in the Meade patent and as described in “First human experience with endoscopically delivered and retrieved duodenal-jejunal bypass sleeve,” Rodriguez-Grunert, et al., Surgery for Obesity and Related Diseases, 4:57-59 (2008).
Despite many advances in the design of intragastric obesity treatment devices, there remains a need for an improved duodenal sleeve that can be implanted for longer periods than before or otherwise address certain drawbacks of previous devices.